<!DOCTYPE html>
<html>
	<head>
		<meta charset="UTF-8">
		<title></title>
	</head>
	<style type="text/css">
	#hh{
		width: 100%;
		background: green;
		font-family: "微软雅黑";
		font-size: 6vw;
		margin: 0 auto;
	}
	
		
	</style>
	<script type="text/javascript">
	  var   arr=['a1','a2','a3','a4','a5','a6','a7','a8','a9','a10'];
	    window.onload=function(){
			var hh=document.getElementById("hh");
			var num=Math.floor(Math.random()*10);
			var btn=document.getElementById("btn");
		    btn.onclick=function(){
	    	hh.innerHTML=arr[num];
	    }
	    
	    }
	   
	</script>
	<body>
		<div id="hh"></div>
		<div class="img"><img src="" alt="" /></div>
		<div class="news">aaaaaaaaa</div>
		<input type="button"  id="btn" value="" />
	</body>
</html>
